"It was very small. Ashton has been going there for year and years," an insider exclusively tells Us Weekly. "It's one of his favorite spots, like home, so it was comfortable and they were well taken care of." Kutcher's friends also helped to rent out the place for the night.

"They had been planning it for awhile. Ashton didn't want a huge thing but they got a good group together," the source adds. "He's certainly changed from how he used to like to party years ago. This was more of a wholesome situation. They had a great time."

The witness adds that the couple of nearly two years "looked romantic together" as they feasted on T-bone steak, shells and cheese with lobster, quail, braised rib and short rib at the French bistro. The cozy setting was perfect for the group to knock back drinks and make "great conversation."

"Mila gets along great with all of his friends," the insider explains to Us. "She's like part of the crew."

Kunis, 30, and her former That '70s Show costar may be well on their way to celebrating another occasion, too -- an engagement. "They talk about getting married and having kids," one pal of the pair recently told Us. "An engagement is imminent."